Effects of homicide timing on test scores: Quasi-experimental evidence from two cities in Colombia.

This study examines the effect of homicides around schools on the standardized test scores of fifth and ninth graders (N = 4729; Mage = 12.71 years, SDage = 2.13) using a quasi-experimental design in two Colombian cities. Exposure to homicides occurring within 7 days of the test and within 500 m of the school decreases test scores by 0.10 SD. Effects show a greater sensitivity to timing than distance, becoming null as the time to the testing date increases but remaining consistent across larger radii. Since students in the study are on average exposed to 12.1 homicides per year, even short-lived learning losses can accumulate to impair learning for substantial portions of the school year. Findings are discussed, considering previous empirical work.